An abiding cliche about Scottish filmmaking it is that it normally paints a grim and depressing picture of the nation.

While there have been obvious exceptions in recent years, such as the musical Sunshine on Leith, you do not normally have to wait long for another tale of drug addiction, violence, poverty and unemployment to unfold.

Davy Henderson of the Fire Engines, one of the post-punk bands featured in BBC documentary Big Gold Dream.

That may explain why two recent documentaries charting key episodes in Scottish musical history have been a breath of fresh air.

The most recent of these, Lost in France by Irish director Niall McCann, relived an era I can firmly recall.

The independent Glasgow record label Chemikal Underground and bands like the Delgados, Mogwai, Bis and Arab Strap were key players in the city in the mid 1990s.

The film has sparked a fond nostalgia for what seems a long bygone era, with the DIY ethos of the label, the makeshift venues and the truly grassroots scene from which the likes of Franz Ferdinand later emerged.

The other film, Big Gold Dream, covered a period of which I have little recollection. Almost everyone with half an interest in Scottish music will have heard of Postcard, the Glasgow label home to Orange Juice and Aztec Camera, which founder Alan Horne ran from his flat on West Princes Street.

But the film also lifts the lid on the little-known story of the indie labels launched by Bob Last and Hilary Morrison from their flat overlooking Edinburgh College of Art, and the ground-breaking packaging and promotional campaigns they created.

Not only did the pair release early records by the Human League and Joy Division, but they were also key players in a thriving post-punk scene in Edinburgh, which boasted bands like Scars, Josef K and the Fire Engines.

Watching Big Gold Dream on its network TV debut on Saturday night, two things struck me. Firstly, the little recognition until the film for the labels Last and Morrison set up and the city’s influence on Britain’s indie music heritage. Director Grant McPhee admits he had never heard of the Edinburgh bands who would end up in Big Gold Dream when he set out to document the story of Postcard.

Secondly, there is something dismaying about the different directions taken by each city’s musical scene by then when viewed from the capital. Glasgow now boasts an array of first-class venues, from the famously intimate King Tut’s to the vast Hydro arena. It is hard to imagine any of them being allowed to close. But it is a far different story at the other end of the M8. Music venues on the doorstep of the art school like the Tap o Lauriston and Cas Rock are long gone, demolished in the name of gentrification. The same fate met the Venue on Calton Road, and the Bongo Club, on New Street.

During recent months, The Picture House, on Lothian Road, has been allowed to be turned into a Wetherspoon pub despite a cultural heritage going back more than half a century, the council sounded the death knell for Electric Circus after giving the go-ahead for the Fruitmarket Gallery to take over its lease, and the Citrus Club will close within weeks.

News of demolition plans for the site of Leith Depot had the feeling of inevitability as the wave of gentrification gradually sweeps down Leith Walk.